1. Field of the Invention
The invention relates to a control apparatus for a vehicle including a continuously variable transmission mechanism and a gear mechanism provided in parallel with each other between an engine and a drive wheel.
2. Description of Related Art
There is well known a power transmission system including a continuously variable transmission mechanism and a gear mechanism provided in parallel with each other between an input rotating member and an output rotating member. The gear mechanism has a gear stage. The power of an engine is transmitted to the input rotating member. The output rotating member outputs the power to a drive wheel. This is, for example, a power transmission system for a vehicle, described in International Application Publication No. 2013/176208. International Application Publication No. 2013/176208 describes the power transmission system for a vehicle, including a power transmission path through a belt-type continuously variable transmission and a power transmission path through a gear train. The power transmission paths are provided in parallel with each other between an input shaft and an output shaft. A first clutch is provided in the power transmission path through the gear train. The first clutch transmits or interrupts power. A second clutch is provided in the power transmission path through the continuously variable transmission. The second clutch transmits or interrupts power. In this power transmission system for a vehicle, the speed ratio of the power transmission path through the gear train is set so as to be higher than the lowest vehicle speed gear ratio (maximum speed ratio) that can be established by the power transmission path through the continuously variable transmission. Thus, when the vehicle starts moving, the first clutch is engaged, and the power of the engine is transmitted by the power transmission path through the gear train, with the result that the vehicle is driven. On one hand, as described in Japanese Patent Application Publication No. 2013-253480 (JP 2013-253480 A), there is a well known neutral control technique for improving fuel economy. In neutral control, while a vehicle is decelerating, an engine load is reduced by placing a clutch, provided in a power transmission path, in a semi-engaged state. On the other hand, there is also a well known idle stop control for temporarily stopping an engine at the time when a vehicle comes to a stop. In this idle stop control, as described in Japanese Patent Application Publication No. 2013-189952 (JP 2013-189952 A), in consideration of drivability (for example, power performance) at the restart of a vehicle, the engine is made to stop when the speed ratio of a transmission is close to the maximum speed ratio.